What's the most expensive thing you've ever lost?

[ddubois]

I could not have accidentally come off, it was tight. I used to wear it all the time, then stopped wearing it for a month, then started again when my wife 'caught' me. It was lost on vacation. I don't remember taking it off; my best guess is that I took it off to go through the metal detector (not only stupid, but completely unnecessary) at the airport, and left it in the bowl. Like $800 value IIRC.